EndlessGridLayoutActivity.java

package com.lzx.demo.ui;

import android.graphics.Color;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;

import com.github.jdsjlzx.ItemDecoration.GridItemDecoration;
import com.github.jdsjlzx.ItemDecoration.SpacesItemDecoration;
import com.github.jdsjlzx.interfaces.OnLoadMoreListener;
import com.github.jdsjlzx.interfaces.OnNetWorkErrorListener;
import com.github.jdsjlzx.interfaces.OnRefreshListener;
import com.github.jdsjlzx.recyclerview.LRecyclerView;
import com.github.jdsjlzx.recyclerview.LRecyclerViewAdapter;
import com.lzx.demo.R;
import com.lzx.demo.adapter.DataAdapter;
import com.lzx.demo.bean.ItemModel;
import com.lzx.demo.util.NetworkUtils;
import com.lzx.demo.view.SampleHeader;

import java.lang.ref.WeakReference;
import java.util.ArrayList;

/**
 * 带HeaderView的分页加载GridLayout RecyclerView
 */
public class EndlessGridLayoutActivity extends AppCompatActivity {

    /**服务器端一共多少条数据*/
    private static final int TOTAL_COUNTER = 24;

    /**每一页展示多少条数据*/
    private static final int REQUEST_COUNT = 10;

    /**已经获取到多少条数据了*/
    private static int mCurrentCounter = 0;

    private LRecyclerView mRecyclerView = null;

    private DataAdapter mDataAdapter = null;

    private PreviewHandler mHandler = new PreviewHandler(this);
    private LRecyclerViewAdapter mLRecyclerViewAdapter = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.sample_ll_activity);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);


        mRecyclerView = (LRecyclerView) findViewById(R.id.list);

        //setLayoutManager must before setAdapter
        GridLayoutManager manager = new GridLayoutManager(this, 2);
        mRecyclerView.setLayoutManager(manager);

        mDataAdapter = new DataAdapter(this);

        mLRecyclerViewAdapter = new LRecyclerViewAdapter(mDataAdapter);
        mRecyclerView.setAdapter(mLRecyclerViewAdapter);

        //设置头部加载颜色
        mRecyclerView.setHeaderViewColor(R.color.colorAccent, R.color.dark ,android.R.color.white);
        //设置底部加载颜色
        mRecyclerView.setFooterViewColor(R.color.colorAccent, R.color.dark ,android.R.color.white);
        //设置底部加载文字提示
        mRecyclerView.setFooterViewHint("拼命加载中","已经全部为你呈现了","网络不给力啊，点击再试一次吧");

        int spacing = getResources().getDimensionPixelSize(R.dimen.dp_4);
        mRecyclerView.addItemDecoration(SpacesItemDecoration.newInstance(spacing, spacing, manager.getSpanCount(), Color.GRAY));

        //根据需要选择使用GridItemDecoration还是SpacesItemDecoration
        GridItemDecoration divider = new GridItemDecoration.Builder(this)
                .setHorizontal(R.dimen.default_divider_padding)
                .setVertical(R.dimen.default_divider_padding)
                .setColorResource(R.color.split)
                .build();
        //mRecyclerView.addItemDecoration(divider);

        mRecyclerView.setHasFixedSize(true);

        mLRecyclerViewAdapter.addHeaderView(new SampleHeader(this));

        //设置span，自己可以体验效果
        /*mLRecyclerViewAdapter.setSpanSizeLookup(new LRecyclerViewAdapter.SpanSizeLookup() {
            @Override
            public int getSpanSize(GridLayoutManager gridLayoutManager, int position) {
                if (position % 4 == 0) {
                    return gridLayoutManager.getSpanCount();
                } else {
                    return 1;
                }

            }
        });*/


        mRecyclerView.setOnRefreshListener(new OnRefreshListener() {
            @Override
            public void onRefresh() {
                mCurrentCounter = 0;
                mDataAdapter.clear();
                requestData();
            }
        });

        mRecyclerView.setOnLoadMoreListener(new OnLoadMoreListener() {
            @Override
            public void onLoadMore() {
                if (mCurrentCounter < TOTAL_COUNTER) {
                    // loading more
                    requestData();
                } else {
                    //the end
                    mRecyclerView.setNoMore(true);
                }
            }
        });

        mRecyclerView.refresh();

    }

    private void notifyDataSetChanged() {
        mLRecyclerViewAdapter.notifyDataSetChanged();
    }

    private void addItems(ArrayList<ItemModel> list) {
        mDataAdapter.addAll(list);
        mCurrentCounter += list.size();
    }

    private class PreviewHandler extends Handler {

        private WeakReference<EndlessGridLayoutActivity> ref;

        PreviewHandler(EndlessGridLayoutActivity activity) {
            ref = new WeakReference<>(activity);
        }

        @Override
        public void handleMessage(Message msg) {
            final EndlessGridLayoutActivity activity = ref.get();
            if (activity == null || activity.isFinishing()) {
                return;
            }

            switch (msg.what) {
                case -1:

                    int currentSize = activity.mDataAdapter.getItemCount();

                    //模拟组装10个数据
                    ArrayList<ItemModel> newList = new ArrayList<>();
                    for (int i = 0; i < 40; i++) {
                        if (newList.size() + currentSize >= TOTAL_COUNTER) {
                            break;
                        }
                        ItemModel item = new ItemModel();
                        item.id = currentSize + i;
                        item.title = "item" + (item.id);

                        newList.add(item);
                    }


                    activity.addItems(newList);

                    activity.mRecyclerView.refreshComplete(10);

                    break;
                case -2:
                    activity.notifyDataSetChanged();
                    break;
                case -3:
                    activity.mRecyclerView.refreshComplete(10);
                    activity.notifyDataSetChanged();
                    activity.mRecyclerView.setOnNetWorkErrorListener(new OnNetWorkErrorListener() {
                        @Override
                        public void reload() {
                            requestData();
                        }
                    });
                    break;
            }
        }
    }

    /**
     * 模拟请求网络
     */
    private void requestData() {

        new Thread() {

            @Override
            public void run() {
                super.run();

                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }

                //模拟一下网络请求失败的情况
                if(NetworkUtils.isNetAvailable(EndlessGridLayoutActivity.this)) {
                    mHandler.sendEmptyMessage(-1);
                } else {
                    mHandler.sendEmptyMessage(-3);
                }
            }
        }.start();
    }

    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_list_drag, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getItemId() == android.R.id.home) {
            finish();
        } else if (item.getItemId() == R.id.menu_grid) {
            mRecyclerView.setLayoutManager(new GridLayoutManager(this, 2));
            mRecyclerView.setAdapter(mLRecyclerViewAdapter);//必须重新setAdapter

        }else if (item.getItemId() == R.id.menu_linear) {
            mRecyclerView.setLayoutManager(new LinearLayoutManager(this));

        }
        return true;
    }
}